1. Field of the Invention
The invention relates to a container for holding liquids and more particularly to a beverage container whose side walls are hollow and inflatable by air so as to provide rigid walls.
2. Description of Related Art
It has long been recognized that when flexible, airtight material is sealed to form an inner chamber, and the inner chamber is filled with air, the flexible material defining the chamber becomes rigid. This principle is exemplified in the ordinary automobile or bicycle tire which becomes more rigid as air is pumped into the inner chamber defined by the flexible material of an inner tube or the tire itself.
Another example of using air under pressure within a chamber to define the shape of the object is the common inflatable children's swimming pool as shown, for example, in U.S. Pat. No. 2,443,440, issued on Jun. 15, 1948 to O. J. Alvarez.
In addition, this inflation principle has been incorporated into inflatable carrying bags such as that disclosed in U.S. Pat. No. 4,164,970, issued to Charles Jordon on Aug. 21, 1979, and in U.S. Pat. No. 4,503,558, issued to Joseph Lief and Michael McCully on Mar. 5, 1985.
Further, inflatable containers for storing trash are disclosed in U.S. Pat. No. 3,556,186, issued to Gerard Besthorne on Jan. 19, 1971, and in U.S. Pat. No. 3,742,994, issued to Philip Pensak on Jul. 3, 1973.
An inflatable container for storing food is disclosed in U.S. Pat. No. 4,085,785, issued Apr. 25, 1978 to Eric Hoot.
Finally, a collapsible container for holding liquids which has inflatable walls is disclosed in U.S. Pat. No. 2,751,953 issued to B. F. Grimm on Jun. 26, 1956. The Grimm container has side walls which are pleated as in the side walls of an accordion. In addition, the "cup" part of the container may be sealed to prevent air within the cup from escaping to the outside. The Grimm container has a series of valves and plugs to allow air to enter the inner chamber formed between the walls of the container when the pleated walls of the container are collapsed and the "cup" sealed so that air may not escape to the outside. The collapsing of the pleated walls of the container forces air within the cup into the inner chamber between the walls under pressure thereby inflating the inner chamber. After the inner chamber has been inflated in this manner and sealed, the "cup" is unsealed so that liquid may be dispensed into or out of the cup of the container.